Implantable tissue connector

ABSTRACT

An implantable tissue connector adapted so as to be connectable to a tubular part of living tissue within a patient&#39;s body, comprising:
         a conduit having at least a first end and a second end and further having an outer surface, wherein between the first and second ends of the conduit or connected to the second end of the conduit, there is provided at least one of the following items: a reservoir in the form of a fecal excrements collecting container or adapted to be filled with at least one medical drug for patient needs, a pump, a motor, a medical device of the following group of devices comprising: a drug delivery system, an artificial urine bladder, an artificial urethra, an artificial esophagus, an artificial trachea, and   at least one flexible sleeve adapted to axially extend and closely fit around at least part of said outer surface of the conduit, wherein the tissue connector is adapted such that the tubular part of living tissue can be located and held in position between the conduit and the flexible sleeve.

BACKGROUND OF THE INVENTION

The present invention relates to an implantable tissue connector that isspecifically adapted to be connected to a tubular part of living tissuewithin a patient's body, such as to the end of the human's large bowelwhen an artificial exit to the large bowel is to be provided. However,the implantable tissue connector of the present invention is not limitedto such application and can be used in connection with many other kindsof tubular living tissue, as will be described in more detail below.

Connecting the end of the human's large bowel to an artificial exit,such as to a fecal excrements collecting container, or connecting ashortened large bowel to the patient's natural intestinal exit hasalways proven difficult and often unreliable. Leakage can occur wherethe connection is not tight over the lifetime. Blood circulation can beprohibited in the end area of the bowel tissue, which can negativelyaffect the muscle functions and peristaltic movement of the bowel andwhich can even lead to starvation of the respective portion of thebowel. Furthermore, the peristaltic movement of the bowel willcontinuously act upon the connection and, thus, the connection can failover time.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide animplantable tissue connector for connecting tubular living tissue in apatient's body, which connection should be reliable over time and notseverely harm the living tissue.

It is a further object to propose different uses for such tissueconnector as well as methods for implanting the tissue connector in apatient's body.

Accordingly, the implantable tissue connector of the present inventioncomprises a conduit with at least a first and a second end and furtherhaving an outer surface on which may be mounted at least one flexiblesleeve axially extending around at least part of said conduit. Accordingto a first embodiment, the flexible sleeve is initially mounted on saidouter surface either folded or rolled upon itself. According to a secondembodiment, the flexible sleeve is initially mounted on said outersurface so as to be foldable upon itself. According to a third, moregeneral embodiment, the flexible sleeve is not initially mounted on theconduit but will be mounted thereon only at the time of implantation ofthe tissue connector in the patient's body.

The first end of the conduit of the tissue connector is connected to atubular part of living tissue by inserting the first end of the conduitinto the tubular part of living tissue. Where, according to the firstembodiment, the flexible sleeve is mounted on the outer surface of theconduit folded or rolled upon itself, the flexible sleeve is unfolded orunrolled such that at least part of the living tissue extending over theconduit's outer surface is located intermediate the sleeve and the outersurface of the conduit. Where, according to the second embodiment, theflexible sleeve is mounted on the outer surface of the conduit so as tobe foldable upon itself, the flexible sleeve is folded upon itself suchthat at least part of the living tissue is located intermediate thefolded sleeve or intermediate the conduit's outer surface and thesleeve. Where, according to the third embodiment, the flexible sleeve isprovided separate from the conduit, the sleeve is advanced over theconduit and the respective portion of tubular tissue such that at leastpart of the living tissue is located intermediate the sleeve and theconduit's outer surface.

Either way, the tubular tissue is located somewhere between the conduitand the flexible sleeve and can be held in that position in variousmanners that will be described in the following and that can be appliedindividually as well as in combination.

The advantages achieved with the tissue connector according to thepresent invention comprise a good sealing of the living tissue betweenthe conduit and the flexible sleeve as well as good protection of theliving tissue by the flexible sleeve. This way, the connection can bemade reliable over time while also protecting the tissue against harm.

Where the flexible sleeve overlaps with the living tissue that has beendrawn over the first end of the conduit, it is desirable that theflexible sleeve will exert radial pressure upon the tissue. Inapplications where there is no movement to be expected, this may besufficient to hold the tissue connector in place. In other instances,where the movement of the tissue material is to be expected, such aswhen used as a bowel connector, the radial pressure will assist inholding the components in place until they are otherwise fixed againstone another. In any case, it is preferable to design the flexible sleevesuch that the radial pressure is minimal so as not to prohibit the bloodcirculation in the living tissue.

Furthermore, the conduit should be designed such that it is lessflexible than the flexible sleeve at least in a radial direction so asto provide support to the sleeve against radial forces, in particularagainst the sleeve's aforementioned radial pressure. This way, the openinternal cross section of the conduit will not be affected by the radialforces caused by the flexible sleeve.

Another particularly preferred way of reliably connecting the livingtissue to the tissue connector involves a flexible sleeve that comprisesa porous ingrowth layer allowing ingrowth of living tissue. This willnot only strengthen any connection between the tissue connector and thetissue but will also serve to further seal the connection against anyleakage.

The ingrowth layer should be made from a material that stimulates tissueingrowth. Preferably, the ingrowth layer has a netlike structure thatcan be penetrated by ingrowing tissue, thereby creating a durableconnection between the living tissue and the flexible sleeve. Of course,the ingrowth layer should be made from a biocompatible material, such asDacron®.

Another way of reliably fixing the living tissue to the tissue connectorconsists in suturing the flexible sleeve to the living tissue.Alternatively, the suturing may be performed through the flexible sleeveand an outer wall of the conduit including an interposed portion of theliving tissue. Thereby, the tissue is fixed to both the flexible sleeveand the conduit. Leakage through needle penetrations caused by thesuturing, if any, will automatically close over time by overgrowingtissue material.

It is also possible to perform the suturing through a portion of theliving tissue and the outer wall of the conduit before the flexiblesleeve is placed over the living tissue. This eliminates any problems ofleakage through the penetration holes caused by the suturing as thesleeve will cover and seal such penetration holes.

Preferably, the thread used for suturing is made from a material that isabsorbable by the patient's body. Typically, the thread will be absorbedby the body within about 6 weeks. At that time, however, the tissueingrowth will be sufficiently advanced to compensate for the loss ofstrength that was initially provided by the thread.

Instead or in addition to suturing the flexible sleeve to the conduit bymeans of a preferably absorbable thread, the sleeve may be fixedlyconnected to the conduit along an axially extending portion of thesleeve in any other appropriate way. For instance, the conduit and thesleeve may be bonded along at least part of said axially extendingportion of the sleeve. A primer may be applied on the conduit's outersurface and/or the flexible sleeve to enhance bonding characteristics.

The flexible sleeve may comprise a multi-layer material. This isparticularly advantageous where the flexible sleeve comprises theaforementioned porous ingrowth layer. For instance, the porous ingrowthlayer might itself not be sufficiently stable to be safely handled andpulled over the tubular tissue and/or the porous ingrowth layer mightnot be able to exert the radial pressure onto the tissue. In either ofthese cases, it is advantageous to provide the flexible sleeve with asupport layer for supporting the porous ingrowth layer.

The support layer may be made e.g. from polyurethane or from expandedpolytetrafluoroethylene (ePTFE). ePTFE is particularly preferred as itcan be designed with pores sufficiently large in size so as to allow forthe necessary exchange of particles and/or elements between theunderlying tissue and the surrounding area of the patient's body.Furthermore, the support layer may give better protection to the tissuethan the ingrowth layer.

It is preferable when after implantation the support layer forms anouter layer of the flexible sleeve or, at least, that the ingrowth layerwill be located radial inward from the support layer. Thus, where theflexible sleeve is mounted on the outer surface of the conduit so as tobe foldable up on itself, the ingrowth layer will be located betweenportions of the support layer when the sleeve is folded upon itself.Alternatively, where the flexible sleeve is mounted on the outer surfaceof the conduit folded or rolled upon itself, the ingrowth layer will belocated radial inward from the support layer when the sleeve is unfoldedor unrolled.

In the regards of materials, both the conduit and the flexible sleeveshould preferably be made from biocompatible material. As far as thesleeve is concerned, it preferably comprises polymers, such aspolytetrafluoroethylene (PTFE), ePTFE, silicone and/or polyurethane.

As far as the conduit is concerned, the same and other biocompatiblepolymer materials can be used, including e.g. polyetheretherketone(PEEK). However, other materials, such as ceramics and metals, inparticular titanium and stainless steel, can be used as well and arepreferable for their strength.

The conduit can be substantially longer than the particular portion ofthe conduit to which the tubular tissue is connected. In that case, itis preferable that the flexible sleeve is located proximately to therespective end of the conduit so that the part of the tissue drawn overthe conduit is not excessively large. The larger the overlapping part ofthe tissue is, the larger may become problems of blood circulationwithin that part of the tissue.

The tissue connector may be intended for connecting with one another twodifferent ends of tubular living tissue. In this case, the conduit mayhave one flexible sleeve at each of the conduit's first and second ends.Again, the flexible sleeves are preferably located proximately to saidfirst and second ends.

In order to facilitate the step of inserting the end or ends of theconduit into the tubular living tissue, it is advantageous to taper thefree end portion of the conduit's end or ends towards the edge of saidfree end portion. Alternatively or in addition, the free end portion maybe provided with a rounded edge. The rounded edge will help to preventany damage to the living tissue when the tissue is pulled over the freeend of the conduit.

According to another particularly preferred embodiment of the invention,there are provided special elements for preventing the tubular tissuefrom slipping off of the conduit. Again, these means can be combinedwith any of the aforementioned options of fixing the living tissue tothe tissue connector.

More particularly, according to this preferred embodiment, the tissueconnector comprises at least one bulge extending outwardly from theconduit's outer surface in a circumferential direction of the conduitabout at least part of the conduit's circumference. Furthermore, atleast one blocking ring is loosely fitted over the outer surface of theconduit with a clearance between the conduit's outer surface and theblocking ring for mounting living tissue within said clearance. Theblocking ring has an inner cross sectional diameter which is smallerthan or substantially identical to an outer cross sectional diameter ofthe at least one bulge so as to prevent the blocking ring from slippingover the bulge when living tissue is mounted within the clearance.

When the tissue connector is implanted in a human being or animal, theliving tissue will be pulled over the conduit's outer surface includingthe bulge. Then the blocking ring will be advanced from the other sideof the bulge over the living tissue towards the bulge such that at leastpart of the living tissue is located intermediate the conduit's outersurface and the blocking ring. This has the effect that, when the tissuetends to slip off of the conduit, it will carry the blocking ringtowards and against the bulge. By this action, the living tissue will becompressed between the bulge and the blocking ring, thereby preventingany further slippage. This effect is self-enhancing with increasingslipping force. As the force tends to decrease again, the compressionforce will decrease accordingly so that blood circulation within theliving tissue will not be negatively affected longer than necessary.

The size of the clearance in a radial direction depends upon theintended use of the tissue connector, i.e. upon the thickness of thetubular living tissue to which the tissue connector is connected.Accordingly, the size may be at average between 0.1 to 0.4 mm, 0.4 to0.8 mm, 0.8 to 1.3 mm, 1.3 to 2 mm, 2 to 3 mm, 3 to 4 mm, 4 to 5 mm,over 5 mm. The clearance should be slightly smaller than the thicknessof the living tissue so as not to severely affect blood circulationwithin the living tissue but nevertheless ensure sufficient frictionalcontact.

While the cross-sectional diameter of the blocking ring shouldpreferably be smaller than the cross-sectional diameter of the bulge, itcan in some instances be identical or even somewhat larger than thisbecause the thickness of the living tissue, even in a compressed state,adds up to the cross-sectional diameter of the bulge so that alltogetherthe blocking ring is prevented from slipping over the bulge. Therefore,in case of particularly thick living tissue, the inner cross-sectionaldiameter of the blocking ring may be even somewhat larger than the outercross-sectional diameter of the bulge.

Of course, it is again preferable to make the blocking ring from abiocompatible material, in particular those materials mentioned abovethat are also suitable for the conduit.

Where the tissue connector is intended to connect two different ends oftubular living tissue material, it may have two of the aforementionedbulges, preferably located proximately to the respective ends of theconduit, with preferably at least two blocking rings locatedintermediate the two bulges. Of course, more than one blocking ringand/or more than one bulge may be provided for each end of the conduit.

As mentioned at the outset, the use of the tissue connector of thepresent invention is not limited to its application at the end of thehuman's large bowel. It can be advantageously used in many otherapplications.

For instance, the tissue connector may be fitted into a human'sesophagus. In this case, the conduit of the tissue connector should havean inner diameter of between 2 and 3.5 cm to provide for a snug fit. Theclearance between the conduit and the blocking ring should be in therange of 2.5 to 5 mm.

Where the tissue connector is connected to a human's trachea, the innerdiameter should be chosen between 1.5 and 2.5 cm, depending upon theposition where at the human's trachea it is to be connected, in order toprovide for a snug fit. The clearance between the conduit and theblocking ring should be in the range of 1 to 2 mm.

Where the tissue connector is fitted into a human stomach, the innerdiameter of the conduit can vary with enlarged boundaries. The clearancebetween the conduit and the blocking ring should be in the range of 3.5to 5 mm.

The tissue connector may also be fitted into a human's gall bladder orits connecting outlet channels. In that case, the conduit should have aninner diameter of between 0.5 and 1.3 cm. The clearance between theconduit and the blocking ring should be in the range of 0.5 to 1.5 mm.

In case that the tissue connector is fitted into a human's small bowel,the inner diameter of the conduit should be between 2 and 3 cm. Theclearance between the conduit and the blocking ring should be in therange of 3 to 4 mm.

In case of the human's large bowel, whose diameter is highlystretchable, the inner diameter of the conduit should be between 3 and5.5 cm to provide for a snug fit. The clearance between the conduit andthe blocking ring should be in the range of 2 to 3.5 mm.

The tissue connector may also be fitted into a human's urethra. In thiscase, the conduit should have an inner diameter of between 0.4 and 0.8cm. The clearance between the conduit and the blocking ring should be inthe range of 0.5 to 1.5 mm.

Also, the tissue connector may be fitted into an human's ureter, inwhich case the inner diameter of the conduit should be chosen between0.4 and 0.7 cm. The clearance between the conduit and the blocking ringshould be in the range of 2 to 4 mm.

The tissue connector may also be connected to the kidney. In order tosnuggly fit it into a human's pelvic part of the kidney, the innerdiameter of the conduit should be in the range of 1 and 5 cm, dependingupon the position where at the human's pelvic it is to be connected. Theclearance between the conduit and the blocking ring should be in therange of 0.5 to 1.5 mm.

The tissue connector may also be fitted into a human's blood vessel. Inthis case, the inner diameter of the conduit should be chosenapproximately similar to the inner diameter of the respective bloodvessel. As an example, the inner diameter may be chosen between 0.1 and0.5 cm in the case of particularly small blood vessels. The tissueconnector may as well be connected to the human's aorta or the heart'satrium or ventricle, in which case the inner diameter of the conduit isin the range of 2 to 3 cm. The clearance between the conduit and theblocking ring should be in the range of 1 to 2 mm.

The tissue connector may also be used as an intermediate piece toreplace a part of tubular living tissue and may as well be used toconnect different types of tubular living tissue, such as where abiological transplant of a third party's body is to be connected to theorgans of a patient.

The tissue connector may particularly be used and be adapted forconnecting it to at last one of an implantable reservoir, an implantablepump, an implantable motor, an implantable medical device and abiological transplant. The artificial items may even form a part of thetissue connector, either integrally formed therewith or separatelyconnected thereto. The reservoir, pump, motor and/or medical device mayalso be incorporated in the tissue connector between the first andsecond ends of the conduit.

The biological transplant may be any transplant, such as a transplantedheart to be connected by means of the tissue connector to the patient'saorta and/or to other blood vessels (pulmonary arteria etc.).

Instead of being artificial, the aforementioned reservoir may consist ofa biological transplant, but it may as well be made from tissue materialof the patient into whom the reservoir is to be implanted. For instance,the reservoir may be a fecal excrements collecting container, such as aurine bladder or an intestine.

The reservoir may also be a reservoir for medical drugs for thepatient's needs and is preferably adapted to be filled with at least onemedical drug. Such medical drug reservoir may or may not be connected toa medical device, such as an implantable drug delivery device, whichmedical device may additionally include a pump for pumping the drug fromthe reservoir into the patient's body and possibly a motor for the pump.

Any other implantable medical devices may also be connected to theorgans of the patient by means of the tissue connector, with or withouta pump, motor and/or reservoir. Examples of these are an artificialheart, a penile prothesis, an artificial urine bladder, an artificialurethra, an artificial esophagus, an artificial trachea and the like.Examples of biological transplants include a urine bladder, anintestine, a urethra, a ureter, a kidney, a bowel, a heart, anesophagus, a trachea, a blood vessel and the like.

The tissue connector of the present invention can be implanted in ahuman being or animal either in open surgery or by subcutaneous surgery.In either case, the skin will have to be cut before free-dissecting anappropriate location within the patient's body adjacent to the tubularliving tissue and, after the conduit of the tissue connector has beenconnected with one or both ends to the tubular tissue, at least the skinwill have to be sutured at the end of the surgery.

Where the tissue connector is implanted by subcutaneous surgery, thesteps of cutting the skin and free-dissecting the appropriate locationwithin the patient's body comprise the steps of

-   -   inserting a needle-like tube into the patient's body, such as        the patient's thorax or abdomen,    -   filling through said needle gas into the patient's body, i.e.        into the thorax cavity or abdomen cavity,    -   cutting a key-hole,    -   inserting at least one, preferably two, laparoscopic trocars        through the key-hole towards said location,    -   advancing one or more medical instruments and a camera through        the at least one trocar towards said location, i.e. into the        thorax or abdomen, and    -   dissecting an area of the tubular part of living tissue with the        aid of the dissecting tool.    -   The tissue connector may be supplied to said location through        the at least one trocar or through a separate incision.

The invention will now be described in more detail in context with somepreferred embodiments of the invention as shown in the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an examplary view of a patient with one tissue connectorconnected to the patient's aorta and another tissue connector connectedto the end of the patient's large bowel.

FIGS. 2 a and 2 b show a cross-section of a first embodiment of thetissue connector in the state of mounting and in the connected state.

FIGS. 3 a and 3 b show a cross-section of an alternative of the firstembodiment of the tissue connector in the state of mounting and in theconnected state.

FIGS. 4 a and 4 b show a second embodiment of the tissue connector inthe state mounting and in the connected state.

FIG. 5 shows an alternative for mounting living tissue on a free end ofthe tissue connector.

FIGS. 6 a and 6 b show a combination of an embodiment similar to the oneshown in FIGS. 2 a and 2 b with additional mounting means as shown inFIG. 5 .

FIG. 7 shows a specific embodiment of a tissue connector with two endsthereof connected to living tissue.

FIG. 1 schematically shows a body 100 of a patient with a first tissueconnector 1 connected to the end of the patient's large bowel 50 and asecond tissue connector 1 a interconnecting two pieces of the patient'saorta 60. The tissue connector 1 may either connect the large bowel 50to the patient's anus or to an artificial anus which may include anexcrements collecting container. The tissue connector 1 a may includebetween its two ends a heart valve, a blood pump, a drug delivery deviceor the like.

The tissue connectors 1 and 1 a shown in FIG. 1 represent only a few ofmany different possible locations and applications of the tissueconnector within the human's or, alternatively, an animal's body.Further examples of possible applications have already been outlinedfurther above.

FIGS. 2 a and 2 b show a first embodiment of the tissue connector 1 inthe state of mounting the tissue connector to a tubular part of livingtissue 70. The tissue connector 1 comprises a conduit 2 with a first end3 and a second end 4. In FIG. 2 a , the first end 3 of the conduit 2 hasalready been inserted into an end portion of living tissue 70. The innercross section of the conduit 2 is selected to approximately match theinner cross section of the tubular living tissue 70 so as not toobstruct any flow of material. The thickness of the wall 5 of theconduit, which is typically circular, is chosen to provide sufficientstrength so that it does not collapse under the forces that will actupon the conduit during use, while providing sufficient flexibilitywhere needed. On the other hand, the thickness should not be chosen toolarge since the living tissue will have to be stretched over the outersurface 6 of the conduit 2 without damage and without excessivelyaffecting blood circulation within the end portion 71 of the livingtissue 70.

The wall 5 of conduit 2 is tapered towards its leading edge 7. Inaddition, the leading edge 7 is rounded. These two measures preventdamage to the living tissue 70 when the conduit 2 is inserted into theend portion 71 of the living tissue 70.

The second end 4 may serve and be adapted to be connected to animplantable medical device, an implantable reservoir, an implantablepump, an implantable motor or a combination of the afore mentioned items(generally designated with 200). It may also be connected to any otherimplantable device 200. The implantable device 200 may even form a partof the tissue connector 1, either integrally or attached thereto.

The implantable device 200 may also be a medical device replacing one ormore of the patient's organs, such as an artificial urine bladder, afecal excrement's collecting container, an artificial urethra, anartificial heart, an artificial esophagus, an artificial trachea or thelike. Alternatively, the second end 4 of the conduit 2 may be connectedto a biological implant obtained from a third party's body, such as aurine bladder, an intestine, a urethra, a ureter, a kidney, a bowel, aheart, an esophagus, a trachea, a blood vessel or the like.

The device 200 may also comprise a flow restrictor for partial orcomplete restriction of flow through the conduit. This can be suitablee.g. in the case where the tissue connector is located at the end of thepatient's large bowel.

The device 200 may also be placed between the tissue connector 1 and asecond tissue connector 1 b with conduit 2 b, as is indicated in FIG. 2a by dotted lines. This arrangement is practical where the device 200has to be placed at a location within one of the patient's organs, suchas in a blood vessel, in which case the blood vessel would be dividedand the device 200 placed between the two tissue connectors 1 and 1 bconnected to the respective free ends of the divided blood vessel. As anexample, the device 200 could include a flow restrictor, such as anartificial heart valve, or a drug delivery reservoir.

Apart from the conduit 2 and the optional device 200, the tissueconnector 1 of the embodiment shown in FIG. 2 a has a flexible sleeve 10axially extending and closely fitted around a part of the outer surface6 of the conduit 2. The flexible sleeve 10 may be delivered separatelyfrom the conduit 2 and placed over the conduit's outer surface 6 shortlybefore implantation into the patient's body. However, it is preferred toprovide the conduit 2 with the flexible sleeve 10 as a unitary item, theflexible sleeve 10 preferably fixed to the outer surface 6 by means ofbonding, welding and/or clamping. In the case of bonding, it can beadvisable to pretreat the outer surface 6 e.g. with a primer, dependingupon the material combination to be bonded together.

In FIG. 2 a , the flexible sleeve 10 is rolled upon itself and can beunrolled over the portion 71 of living tissue 70 so as to cover, sealand protect that portion 71 on the first end 3 of the conduit 2, as isshown in FIG. 2 b . The tissue portion 71 and the overlapping part 11 offlexible sleeve 10 are fixed to the first end 3 of the conduit 2 bysuturing threads 20 therethrough and through the wall 5 of the conduit2, as is indicated in FIG. 2 b by dotted lines.

The flexible sleeve 10 is a multilayer material comprising a porousingrowth layer to allow ingrowth of living tissue. For that, it has anetlike structure. On top of the ingrowth layer 11 there is provided asupport layer 12. The support layer 12 may have one ore more of variousfunctions. One possible function is to provide support to the ingrowthlayer 11 so as to ease handling and/or prevent fussing of the ingrowthlayer. Also, the support layer 12 may provide some tension, therebyexerting a compressive force in a radial direction so as to slightlyclamp the tissue portion 71 against the outer surface 6 of the conduit2. For that, the support layer should have an appropriate elasticity.Finally, the support layer may provide protection for the tissue portion71.

Preferably, the support layer should be porous so that exchange betweenthe tissue portion 71 and the surrounding area within the patient's bodyis possible. This is an important aspect for the ingrowth of livingtissue material into the ingrowth layer 11. Expandedpolytetrafluoroethylene (ePTFE) is particularly suitable, as it isflexible, inert and can be made with any desired porosity. Otherbiocompatible polymers, such as polyurethane and the like, are suitableas well.

FIGS. 3 a and 3 b show an alternative of the first embodiment of thetissue connector which differs from the connector shown in FIGS. 2 a and2 b solely by the fact that the flexible sleeve 10 is not rolled uponitself but, instead, folded upon itself. By unfolding the folded sleeve10, it can be placed over the tissue portion 71 in the same manner asdiscussed above in relation to FIGS. 2 a, 2 b , as is shown in FIG. 3 b.

FIGS. 4 a and 4 b show a second embodiment of a tissue connector wherethe flexible sleeve 10 is arranged such that it is foldable upon itself.More particularly, the first end 3 of the conduit 2 is inserted in thetissue portion 71 of living tissue 70 to an extent that it overlaps afirst portion 13 of the flexible sleeve 10. The remaining portion 14 ofthe flexible sleeve 10 not being covered by the tissue portion 71 isrolled upon itself and can be unrolled so as to cover the tissue portion71. As a result shown in FIG. 4 b , the flexible sleeve 10 is foldedupon itself with the tissue portion 71 placed intermediate the foldedsleeve 10.

Different to the embodiments described before, suturing the tissueportion 71 to the wall 5 of the conduit 2 is carried out before thetissue portion 71 is covered with the remaining part 14 of the flexiblesleeve 10. The remaining part 14 thereby seals any penetration holescaused by the suturing.

In an alternative of the second embodiment, not shown, the first end 3of the conduit 2 will be inserted in the tissue portion 71 only so farthat the tissue portion 71 does not overlap with the flexible sleeve 10.Thus, after unrolling the flexible sleeve 10, only a part of the foldedsleeve 10 will cover the tissue portion 71.

Furthermore, also not shown, the remaining part 14 of the sleeve 10 isnot necessarily rolled upon itself, as shown in FIG. 4 a , but may layflat against the outer surface 6 of the conduit 2, similar to theembodiment shown in FIG. 3 a .

As will be recognized, the portion 13 of the flexible sleeve 10 isarranged in a circumferential groove provided in the outer surface 6 ofthe conduit 2. It is advantageous when the depth of the groovecorresponds to the thickness of the flexible sleeve 10. This willfacilitate introducing the first end 3 of the conduit 2 into the livingtissue 70.

FIG. 5 shows a possibility of fixing the conduit 2, such as theconduit's second end 4, to a tubular part of living tissue 80 or to ahose that belongs or leads to a medical device, reservoir, or the like.Accordingly, at least one bulge 15 extends outwardly from the conduit'souter surface 6 in a circumferential direction of the conduit 2 about atleast a part of the conduit's circumference. Furthermore, at least oneblocking ring 30 loosely fitting over the outer surface 6 of the conduit2 with a clearance between the outer surface 6 and the blocking ring 30is provided for mounting the tubular living tissue 80 (or alternativelythe hose) within the clearance. The blocking ring has an innercross-sectional diameter which is about the same as the outercross-sectional diameter of the bulge 15. This prevents the blockingring from slipping over the bulge when the living tissue 80, as shown inFIG. 5 , is mounted within the clearance.

When an axial force tends to pull the tubular living tissue 80 from theouter surface 6 of the conduit 2, the blocking ring 30 will move withthe tubular tissue 80, thereby compressing the tubular tissue 80 againstthe bulge 15, so as to prevent any further slippage of the tubulartissue 80 over the bulge 15. This is a self-enhancing effect.

This kind of locking mechanism can be combined with any of theaforementioned embodiments of the tissue connector. Of these variants,only one shall examplary be described in the following in relation toFIGS. 6 a and 6 b . The embodiment shown in FIGS. 6 a and 6 bsubstantially correspond to the embodiment of FIGS. 2 a and 2 b , wherethe flexible sleeve 10 is rolled upon itself and then unrolled to coverthe tubular tissue 80 which, in this case, is pulled over the second end4 of the conduit 2 sufficiently far so as to extend also over the bulge15. After the flexible sleeve 10 has been unrolled over the tubulartissue 80, the blocking ring 30 is pushed over the flexible sleeveagainst the bulge 15. After a while, the threads 20 sutured to thetubular tissue 80 and the wall 5 of the conduit 2 (FIG. 6 a ) will havebeen absorbed by the patient's body and, about during the same time,living tissue will have formed in and connect the tubular tissue 80 tothe ingrowth layer 11 of the flexible sleeve 10. Therefore, as thetubular tissue 80 tends to be pulled off of the second end 4 of theconduit 2, the blocking ring 30 will also be moved, press the tubulartissue 80 and the flexible sleeve 10 against the bulge 15 and therebyprohibit any further slippage of the tubular tissue 80 over the bulge15. The friction coefficient between the blocking ring 30 and the outersurface of the flexible sleeve should be higher than the frictioncoefficient which the conduit's outer surface 6 has in relation to thetubular tissue 80.

Note that the flexible sleeve 10 in its unrolled state as shown in FIG.6 b must not necessarily extend over the bulge 15 but can end a distanceaway from the bulge. In that situation, the blocking ring 30 would notclamp the sleeve 10 against the bulge 15.

The afore mentioned embodiments have mainly been described in relationto a tissue connector of which only one of the two ends is intended tobe connected to tubular living tissue. However, as has also beenmentioned before, there are various applications where the tissueconnector may connect two pieces of tubular living tissue, such as whenbridging two pieces of identical tubular living tissue or connectingtubular living tissue with tissue of a biological transplant. For that,the second end 4 of the tissue connector's conduit 2 can be designedaccording to any of the aforementioned embodiments. FIG. 7 gives just anexample of how such tissue connector could be designed. Accordingly, twoflexible sleeves 10 are integrally formed to form a single flexiblesleeve 10 a, with each of the sleeves 10 being rolled upon itself,similar to the embodiment shown in FIG. 2 a . The two flexible sleeves10 can, of course, be provided separately. Furthermore, a bulge 15 and ablocking ring 30 can be provided at one or both of the conduit's ends 3and 4. Also, a medical device, flow restrictor or the like can beincorporated intermediate the two ends 3 and 4.

1. (canceled)
 101. An implantable tissue connector adapted so as to beconnectable to a tubular part of living tissue within a patient's body,comprising: a conduit having at least a first end and a second end andfurther having an outer surface, wherein between the first and secondends of the conduit or connected to the second end of the conduit, thereis provided at least one of the following items: a reservoir in the formof a fecal excrements collecting container or adapted to be filled withat least one medical drug for patient needs, a pump, a motor, a medicaldevice of the following group of devices comprising: a drug deliverysystem, an artificial urine bladder, an artificial urethra, anartificial esophagus, an artificial trachea, and at least one flexiblesleeve adapted to axially extend and closely fit around at least part ofsaid outer surface of the conduit, wherein the tissue connector isadapted such that the tubular part of living tissue can be located andheld in position between the conduit and the flexible sleeve.
 102. Theimplantable tissue connector of claim 101, wherein the conduit is madefrom a biocompatible material, wherein the biocompatible material ispreferably a material of the following group of materials comprising:titanium, stainless steel, ceramics, polytetrafluoroethylene (PTFE),expanded polytetrafluoroethylene (ePTFE), polyetheretherketone (PEEK),silicone, polyurethane, polypropylene, other biocompatible polymermaterial.
 103. The implantable tissue connector of claim 101, whereinsaid flexible sleeve is mounted on said outer surface either folded orrolled upon itself or so as to be foldable upon itself, wherein, wherethe flexible sleeve is mounted on the outer surface of the conduit so asto be foldable upon itself, the flexible sleeve, when folded uponitself, will exert radial pressure.
 104. The implantable tissueconnector of claim 101, said flexible sleeve is mounted on said outersurface either folded or rolled upon itself or so as to be foldable uponitself, wherein, where the flexible sleeve is mounted on the outersurface of the conduit folded or rolled upon itself, the flexiblesleeve, when unfolded or unrolled, will exert radial pressure.
 105. Theimplantable tissue connector of claim 104, wherein, when implanted in apatient's body with the sleeve unfolded or unrolled, the tissueconnector is adapted to exert said radial pressure on any living tubulartissue placed intermediate the sleeve and the outer surface of theconduit.
 106. The implantable tissue connector of claim 101, wherein theconduit is less flexible than the flexible sleeve at least in a radialdirection so as to provide support to the sleeve against radial forces.107. The implantable tissue connecter of claim 101, wherein the conduitand the flexible sleeve are fixedly connected to each other along anaxially extending portion of the sleeve.
 108. The implantable tissueconnector of claim 107, wherein the conduit and the flexible sleeve arebonded along at least part of said axially extending portion of the,wherein preferably the tissue connector comprises a primer on at leastone of the conduit and the flexible sleeve to enhance bondingcharacteristics.
 109. The implantable tissue connector of claim 101,wherein the at least one flexible sleeve is located proximately to saidfirst end of the conduit.
 110. The implantable tissue connector of claim101, wherein the conduit has at least two of said flexible sleeves,wherein preferably the at least two flexible sleeves are each locatedproximately to one of said at least first and second ends of theconduit.
 111. The implantable tissue connector of claim 101, wherein thefirst end of the conduit has a free end portion and tapers towards theedge of said free end portion.
 112. The implantable tissue connector ofclaim 101, wherein the first end of the conduit has a free end portionwith a rounded edge.
 113. The implantable tissue connector of claim 101,wherein the conduit has an inner diameter of between 0.1 and 0.5 cm orbetween 0.5 and 1 cm or between 1 and 2 cm or between 2 and 3 cm orbetween 3 and 4 cm, or, an inner diameter of 4 cm or over.
 114. Theimplantable tissue connector of claim 101, wherein said conduit is sizedso as to be snuggly fitted into a human's esophagus.
 115. Theimplantable tissue connector of claim 101, wherein said conduit is sizedso as to be snuggly fitted into a human's trachea.
 116. The implantabletissue connector of claim 101, wherein said conduit is sized so as to besnuggly fitted into a human's stomach.
 117. The implantable tissueconnector of claim 101, wherein said conduit is sized so as to besnuggly fitted into a human's gall bladder or its connecting outletchannels.
 118. The implntable tissue connector of claim 101, whereinsaid conduit is sized so as to be snuggly fitted into a human's smallbowel or large bowel.
 119. The implantable tissue connector of claim101, wherein said conduit is sized so as to be snuggly fitted into ahuman's urethra or ureter.
 120. The implantable tissue connector ofclaim 101, wherein said conduit is sized so as to be snuggly fitted intoa human's pelvic part of the kidney.